The Goodwyn Field - An Integrated Approach to Optimal Field Development

Steve H. Newman and Neil C. Taylor

The Goodwyn gas field is located some 130km offshore of Western Australia in a water depth of 130m and is currently under development. First production commenced in February 1995. The rich gas (CGR - 90 bbl/MMscf) is trapped within fluvio-deltaic reservoirs of the Triassic Mungaroo Formation in a large rotated fault block on the northwestern edge of the Dampier Sub-Basin. The reservoir units, ranging In thickness between 30 and 80 metres, dip gently below the overlying Cretaceous shales which provide the updip seal. The target production levels and ultimate recovery are based on the optimisation of gas recycling along strike in the individual reservoir units. The success of the development plan depends on an accurate model of the reservoir architecture. Prior to developme t drilling, only four wells had penetrated the primary reservoir units. Successful development planning required the recognition and management of key subsurface uncertainties. Integration between seismic interpretation, stochastic reservoir modelling and reservoir engineering proved essential to achieve the development objectives. A detailed evaluation of the reservoir stratigraphy, sedimentology, high resolution seismic and high resolution palynology, provided the framework for the 3D stochastic reservoir modelling. The modelling converted the information into a number of geological realisations which were then used to generate a family of dynamic reservoir models. The location of the various development wells was thus optimised on a risked basis. Seven development wells have now been rilled and although these wells have shown that there is more variability than originally envisaged, the broad framework of the reservoir model remains robust

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California